Recherche Page web : https://www.college-de-france.fr/site/en-cirb/Turlier.htm. Introduction Invaluable progress has been made last decades in the molecular, genetic and cellular characterization of morphogenetic processes. Yet, the precise physical processes governing the shape and dynamics of cells remain poorly characterized. The laboratory is developing theoretical models of morphogenesis, combining physics, mechanics and advanced numerical simulations. To understand how morphology contro..

Turlier, Hervé

OpenEdition

 
L’annuaire du Collège de France
Cours et travaux 
118 | 2020
Annuaire du Collège de France 2017-2018
Physique multi-échelle de la morphogénèse / 
Multiscale physics of morphogenesis
Centre interdisciplinaire de recherche en biologie (CIRB)
Hervé Turlier
Electronic version
URL: https://journals.openedition.org/annuaire-cdf/16168
DOI: 10.4000/annuaire-cdf.16168
ISBN: 978-2-7226-0572-5
ISSN: 2109-9227
Publisher
Collège de France
Printed version
Date of publication: 30 December 2020
Number of pages: 666-668
ISBN: 978-2-7226-0516-9
ISSN: 0069-5580
 
Electronic reference
Hervé Turlier, “Physique multi-échelle de la morphogénèse / Multiscale physics of morphogenesis”, 
L’annuaire du Collège de France [Online], 118 | 2020, Online since 01 April 2021, connection on 31 May
2021. URL: http://journals.openedition.org/annuaire-cdf/16168 ; DOI: https://doi.org/10.4000/
annuaire-cdf.16168 
Collège de France
666 AUTRES ENSEIGNEMENTS ET RECHERCHES
[8]  JANAKIRAMAN A., FIXEN K.R., GRAY A.N., NIKI H. et GOLDBERG M.B., « A genome-
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Communications, vol. 9, no 1, 2018, p. 2027, DOI : 10.1038/s41467-018-04414-2.
PUBLICATIONS
THOMASSIN J.-L., SANTOS MORENO J., GUILVOUT I., TRAN VAN NHIEU G. et FRANCETIC O., 
« The trans-envelope architecture and function of the type 2 secretion system: new insights 
raising new questions », Molecular Microbiology, vol.  105, no  2, 2017, p.  211-226, DOI : 
10.1111/mmi.13704.
COLLET C., THOMASSIN J.-L., FRANCETIC O., GENEVAUX P. et TRAN VAN NHIEU G., « Protein 
polarization driven by nucleoid exclusion of DnaK(HSP70)-substrate complexes », Nature 
Communications, vol. 9, no 1, 2018, p. 2027, DOI : 10.1038/s41467-018-04414-2.
SMAIL Y., SUN C., COMBETTES L. et TRAN VAN NHIEU G., « Imaging Ca2+ responses during 
Shigella infection of epithelial cells », Journal of Visualized Experiments, no 135, 2018, DOI : 
10.3791/57728.
VALENCIA-GALLARDO  C., BOU-NADER  C., AGUILAR  D., CARAYOL  N., QUENECH’DU  N., 
PECQUEUR L., PARK H., FONTECAVE M., IZARD T. et NHIEU G.T.V., « Cell adhesion promoted 
by a unique Shigella IpaA vinculin- and talin-binding site », BioRxiv, 2018, 329136, DOI : 
10.1101/329136.
TRAN VAN NHIEU  G., DUPONT  G. et COMBETTES  L., « Ca2+ signals triggered by bacterial 
pathogens and microdomains », Biochimica Et Biophysica Acta. Molecular Cell Research, 
vol. 1865, no 11 B, 2018, p. 1838-1845, DOI : 10.1016/j.bbamcr.2018.08.007.
PHYSIQUE MULTI-ÉCHELLE DE LA MORPHOGÉNÈSE / 
MULTISCALE PHYSICS OF MORPHOGENESIS
Responsables : Hervé TURLIER
RECHERCHE
Page web : https://www.college-de-france.fr/site/en-cirb/Turlier.htm.
Introduction
Invaluable progress has been made last decades in the molecular, genetic and 
cellular characterization of morphogenetic processes. Yet, the precise physical 
processes governing the shape and dynamics of cells remain poorly characterized. 
 éqUIPES ACCUEILLIES AU COLLèGE DE FRANCE 667
The laboratory is developing theoretical models of morphogenesis, combining 
physics, mechanics and advanced numerical simulations. To understand how 
morphology controls biological functions, and, ultimately, how multicellular 
systems self-organize, we aim at integrating molecular, cellular and multicellular 
levels of description into a new and versatile simulation framework for embryo 
morphogenesis: Virtual Embryo.
From molecular to mesoscopic models of the actomyosin cortex
As elegantly illustrated by D’Arcy Thompson back in 1917, cells in suspension or 
in tissues adopt spatial configurations remarkably similar to soap bubbles, an 
analogy which can be drawn from the physical concept of surface tension. In animal 
cells, the surface tension is mainly provided by the contractile forces generated by 
molecular motors within the actin-myosin (or actomyosin) cortex, a thin layer of 
polymeric filaments, which lies under the plasma membrane. In contrast to passive 
objects like bubbles, cortical tension is actively regulated in space and time by 
several biochemical pathways – such as the RhoA signaling cascade – and strongly 
depends on the deformations of the layer. From a biological perspective, the tools 
available to perturb the cortex operate at the molecular level (chemical drugs, genetic 
engineering and environmental cues). Characterizing quantitatively how the self-
organization and regulation of molecular players in the cortex (actin filaments, 
myosin motors, crosslinkers...) control its coarse-grained physical properties 
(elasticity, fluidity, contractility...) represents therefore a critical step to directly 
relate experiments to quantitative models. 
At the cellular scale, the recent active-gel hydrodynamic theories have proven 
their efficiency in capturing the essential physics of various actomyosin based 
dynamical cell processes (Turlier et al., 2014). However their relation to microscopic 
properties of actomyosin networks remains unclear, and no generic tool is available 
to simulate the mechanics of active surfaces in 3 dimensions. Combining physics 
and numerical simulations, we aim at filling these gaps in the next years in close 
collaboration with experimental groups.
From cellular to multicellular models of morphogenesis
At the multicellular level, morphogenesis is furthermore regulated by mechanical 
interaction and biochemical communication between cells, and by external 
mechanical constraints. In particular, the interplay between cell contractility, cell-
cell adhesion, molecular expression and fate specification remains poorly understood 
in early embryos and small tissues. To identify and understand the minimal self-
organization principles driving multicellular morphogenetic processes, it is essential 
to develop realistic 4-dimensional models of interacting cells, offering general and 
accurate description of cell surface mechanics but also complemented by versatile 
options to model surface signaling dynamics and simple gene networks regulation. 
The morphogenesis of early embryos is the main biological focus and guideline for 
developing new theoretical tools in the laboratory. In mammalian species, early 
embryos develop over several days, which leads to a decoupling between 
morphogenetic timescales (several hours) and typical viscous relaxation timescales (a 
few minutes). Dynamics is limited in this case first by the slow regulation of surface 
668 AUTRES ENSEIGNEMENTS ET RECHERCHES
tensions, and morphogenesis is well captured by a quasi-static mechanical description, 
as we recently proposed for compaction and for the formation of the inner-cell mass in 
the mouse embryo (Maître, Turlier et al., 2016). At the opposite, most non-mammalian 
embryo types, such as marine animals or insects, develop on much shorter timescales, 
of the order of a few hours. In this case, viscous dissipation becomes essential to 
consider again as it constitutes a main factor limiting cell shape dynamics (Turlier et 
al., 2014). On such timescales, the biophysical characterization and precise modeling 
of cell divisions and its mechanical coupling to the rest of the embryo is an essential 
point that we aim to integrate into realistic simulations of embryo morphogenesis.
Références citées
TURLIER  H., AUDOLY  B., PROST  J. et JOANNY  J.-F., « Furrow constriction in animal cell 
cytokinesis », Biophysical Journal, vol.  106, no  1, 2014, p.  114-123, DOI : 10.1016/j.
bpj.2013.11.014.
MAÎTRE J.-L., TURLIER H., ILLUKKUMBURA R., EISMANN B., NIWAYAMA R., NÉDÉLEC F. et 
HIIRAGI T., « Asymmetric division of contractile domains couples cell positioning and fate 
specification », Nature, vol. 536, no 7616, 2016, p. 344-348, DOI : 10.1038/nature18958.
DYNAMIQUE ET PHYSIOPATHOLOGIE DES RÉSEAUX NEURONAUX / 
DYNAMICS AND PHYSIOPATHOLOGY OF NEURONAL NETWORKS
Responsable : Laurent VENANCE
RECHERCHE
Page web : https://www.college-de-france.fr/site/en-cirb/venance.htm.
Our main interest is how neural networks of the brain support its cognitive 
capacities. We aim at providing rational mechanistic explanations of adaptative 
control of behavior. Procedural learning corresponds to the acquisition of skills 
through repeated performance and practice of a behavior in response to external 
cues, such as biking or playing an instrument. Basal ganglia, a set of subcortical 
nuclei, participate in the detection of environmental cues and in the selection of 
appropriate actions based on motivation and reward, thanks to their reciprocal 
connections to the cerebral cortex and limbic system. Cortex-basal ganglia loops are 
involved in the adaptive control of behavior and are the main substrate for procedural 
learning. We therefore focus our work on dissecting the processing of information in 
cortico-basal ganglia circuits, from sub-cellular to neural network levels. The key 
roles of basal ganglia are highlighted by motor and cognitive disorders observed in 
pathologies such as Parkinson diseases, for which no fully satisfying treatments are 
available yet.
Our main focus is about the role of the striatum, the primary input nucleus of basal 
ganglia, which is a strategic gate extracting pertinent information and a major site of 
memory formation. Indeed, striatum acts as a coincidence detector of distributed 
patterns of cortical and thalamic activity and is in charge to extract pertinent 
information from background noise at a t time in a given situation, which will give 


Physique multi-échelle de la morphogénèse / Multiscale physics of morphogenesis

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Physique multi-échelle de la morphogénèse / Multiscale physics of morphogenesis

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